1. Field of the Invention
The present invention relates generally to a wastewater treatment device and a treatment method of wastewater, and more particularly to a fluidized bed reactor and a method applying the same.
2. Description of the Related Art
The traditional nitrification-denitrification is one of the most widespread biotechnology for nitrogen removal in wastewater treatment plants. However, this biological process has been challenged by anaerobic ammonia oxidation (Anammox) process due to its more energy saving. In anammox reaction, ammonia and nitrite act as electron donor and accepter, respectively, to yield nitrogen gas and nitrate.
It is recognized that anammox process is used to treat wastewaters with high nitrogen concentration (more than 500 mg N/L) at mesophilic temperature. The main reason is due to the slow growth of anammox bacteria. Once the infeed ammonia nitrogen concentration is low, the start-up of the bioreactor can be significantly increased. Even worth, if the infeed ammonia nitrogen is too low, the bio-system based on anammox bacteria might not be built successfully. Since municipal wastewater has low nitrogen concentration, normally ranging from 20-85 mg N/L, there is a saying that anammox process cannot treat municipal wastewater efficiently.